/*	$OpenBSD: cat.c,v 1.31 2020/12/11 05:48:22 cheloha Exp $	*/
/*	$NetBSD: cat.c,v 1.11 1995/09/07 06:12:54 jtc Exp $	*/

/*
 * Copyright (c) 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Kevin Fall.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/types.h>
#include <sys/stat.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "compat.h"


#define MAXIMUM(a, b) (((a) > (b)) ? (a) : (b))

int bflag, eflag, nflag, sflag, tflag, vflag;
int rval;

void cook_args(char *argv[]);
void cook_buf(FILE *, const char *);
void raw_args(char *argv[]);
void raw_cat(int, const char *);

int main(int argc, char *argv[]) {
  setprogname(argv[0]);
  int ch;

  while ((ch = getopt(argc, argv, "benstuv")) != -1) {
    switch (ch) {
    case 'b':
      bflag = nflag = 1; /* -b implies -n */
      break;
    case 'e':
      eflag = vflag = 1; /* -e implies -v */
      break;
    case 'n':
      nflag = 1;
      break;
    case 's':
      sflag = 1;
      break;
    case 't':
      tflag = vflag = 1; /* -t implies -v */
      break;
    case 'u':
      setvbuf(stdout, NULL, _IONBF, 0);
      break;
    case 'v':
      vflag = 1;
      break;
    default:
      fprintf(stderr, "usage: %s [-benstuv] [file ...]\n", getprogname());
      return 1;
    }
  }
  argv += optind;

  if (bflag || eflag || nflag || sflag || tflag || vflag)
    cook_args(argv);
  else
    raw_args(argv);
  if (fclose(stdout))
    err(1, "stdout");
  return rval;
}

void cook_args(char **argv) {
  FILE *fp;

  if (*argv == NULL) {
    cook_buf(stdin, "stdin");
    return;
  }

  for (; *argv != NULL; argv++) {
    if (!strcmp(*argv, "-")) {
      cook_buf(stdin, "stdin");
      clearerr(stdin);
      continue;
    }
    if ((fp = fopen(*argv, "r")) == NULL) {
      warn("%s", *argv);
      rval = 1;
      continue;
    }
    cook_buf(fp, *argv);
    fclose(fp);
  }
}

void cook_buf(FILE *fp, const char *filename) {
  unsigned long long line;
  int ch, gobble, prev;

  line = gobble = 0;
  for (prev = '\n'; (ch = getc(fp)) != EOF; prev = ch) {
    if (prev == '\n') {
      if (sflag) {
        if (ch == '\n') {
          if (gobble)
            continue;
          gobble = 1;
        } else
          gobble = 0;
      }
      if (nflag) {
        if (!bflag || ch != '\n') {
          fprintf(stdout, "%6llu\t", ++line);
          if (ferror(stdout))
            break;
        } else if (eflag) {
          (void)fprintf(stdout, "%6s\t", "");
          if (ferror(stdout))
            break;
        }
      }
    }
    if (ch == '\n') {
      if (eflag && putchar('$') == EOF)
        break;
    } else if (ch == '\t') {
      if (tflag) {
        if (putchar('^') == EOF || putchar('I') == EOF)
          break;
        continue;
      }
    } else if (vflag) {
      if (!isascii(ch)) {
        if (putchar('M') == EOF || putchar('-') == EOF)
          break;
        ch = toascii(ch);
      }
      if (iscntrl(ch)) {
        if (putchar('^') == EOF ||
            putchar(ch == '\177' ? '?' : ch | 0100) == EOF)
          break;
        continue;
      }
    }
    if (putchar(ch) == EOF)
      break;
  }
  if (ferror(fp)) {
    warn("%s", filename);
    rval = 1;
    clearerr(fp);
  }
  if (ferror(stdout))
    err(1, "stdout");
}

void raw_args(char **argv) {
  int fd;

  if (*argv == NULL) {
    raw_cat(fileno(stdin), "stdin");
    return;
  }

  for (; *argv != NULL; argv++) {
    if (!strcmp(*argv, "-")) {
      raw_cat(fileno(stdin), "stdin");
      continue;
    }
    if ((fd = open(*argv, O_RDONLY, 0)) == -1) {
      warn("%s", *argv);
      rval = 1;
      continue;
    }
    raw_cat(fd, *argv);
    close(fd);
  }
}

void raw_cat(int rfd, const char *filename) {
  int wfd;
  ssize_t nr, nw, off;
  static size_t bsize;
  static char *buf = NULL;
  struct stat sbuf;

  wfd = fileno(stdout);
  if (buf == NULL) {
    if (fstat(wfd, &sbuf) == -1)
      err(1, "stdout");
    bsize = MAXIMUM(sbuf.st_blksize, BUFSIZ);
    if ((buf = malloc(bsize)) == NULL)
      err(1, NULL);
  }
  while ((nr = read(rfd, buf, bsize)) != -1 && nr != 0) {
    for (off = 0; nr; nr -= nw, off += nw) {
      if ((nw = write(wfd, buf + off, nr)) == -1 || nw == 0)
        err(1, "stdout");
    }
  }
  if (nr == -1) {
    warn("%s", filename);
    rval = 1;
  }
}
